1. Field of the Invention
The present invention relates to an ink jet recording method, wherein two ink compositions are deposited onto a recording medium, and an ink set used therefor.
2. Background Art
An ink jet recording method is a printing method wherein droplets of an ink composition are ejected and deposited onto a recording medium such as paper. This method has a feature that an image having a high resolution and a high quality can be printed at a high speed with a relatively inexpensive apparatus. In general, the ink composition used in the ink jet recording comprises water as a main component and, added thereto, a colorant and a wetting agent such as glycerin added for prevention of clogging and other purposes.
On the other hand, a new ink jet recording method has been recently proposed which comprises applying a polyvalent metal salt solution onto a recording medium and then applying an ink composition containing a dye material having at least one carboxyl group (see e.g., Japanese Patent Laid-Open No. 202328/1993). The claimed advantage of this method is that polyvalent metal ions combine with the dye to form an insoluble composite which can provide an image having water resistance and a high quality free from color bleeding.
Further, an ink jet recording method has been proposed wherein a first ink composition containing a pH-sensitive dye is used in combination with a second ink composition having such a pH value as will cause precipitation of the pH-sensitive dye (Japanese Patent Laid-Open No. 208548/1993). The claimed advantage of this method is that use of these two ink compositions can realize an image having water resistance and high quality free from color bleeding.
Further, an ink jet recording method has been proposed wherein a color ink containing at least a surfactant or a penetrable solvent and a salt for imparting a penetrating property is used in combination with a black ink which cooperates with the salt to cause thickening or coagulation, thereby providing a high-quality color image having a high image density and free from color bleeding (Japanese Patent Laid-Open No. 106735/1994). More specifically, in this method, two liquids, i.e., a first liquid containing a salt and a second liquid of an ink composition, are printed to provide a good image.
Furthermore, other ink jet recording methods wherein two liquids are printed have been proposed, for example, in Japanese Patent Laid-Open Nos. 240557/1991 and 240558/1991.